The heavy-duty vehicle industry typically utilizes wheel end assemblies on opposite ends of one or more axles. Each wheel end assembly typically includes a hub mounted on a bearing assembly. The bearing assembly is mounted on an outboard end a spindle of the wheel end assembly, to enable rotation of the hub relative to the spindle.
The spindle is typically joined to a tubular end portion of an axle by a welding operation to form an axle and wheel end assembly. A weld joint between the spindle and the tubular portion of the axle experiences heavy loads that induce localized deflection, distortion and stress around the weld joint. There is also a region near the weld joint that can potentially be detrimentally affected by heat and stress concentrations generated during the welding operation. Thus, the tubular portion of the axle and the end portion of the spindle components are often selected to be of dimensions and materials that can withstand the loads and stresses that a heavy-duty vehicle encounters in operation, as well as the heat and stress concentrations that are generated during manufacture of the axle and wheel end assembly.
Previously known axle and wheel end assemblies for a heavy-duty vehicle typically incorporate a standard size tubular portion of the axle. An issue with currently known joining is that it can be sensitive to geometry of the components. That is, a skirt wall thickness of a spindle needs to be substantially similar to the wall thickness of the tubular portion of the axle in order to get a desirable curl shape of weldment residual material during the joining operation. Inner and outer diameters of the spindle skirt and the inner and outer diameters of the tubular portion of the axle also impact the curl shape of the weldment residual material. A desirable curl shape without a sharp edge is important for getting acceptable integrity and fatigue life from the axle tubular portion to spindle weld joint. Joints that have an undesirable curl shape would generally result in scrapping of the axle and wheel end assemblies, thereby adding to the overall cost of manufacturing.
Axle and wheel end assemblies also include brake component retention or mounting structure, commonly known as a spider or torque plate. The brake component retention or mounting structure is typically fixed to the axle or to the spindle. The location of the spider or torque plate along the axle is generally determined by the brake system structure and user requirements. The location of the spider or torque plate is typically axially spaced from the weld joint between the spindle and the axle.
The previously known axle and wheel end assemblies tend to be relatively heavy which contributes to the overall weight of the heavy-duty vehicle and, therefore, limit the amount of cargo that may be legally carried by the heavy-duty vehicle. The previously known axle and wheel end assemblies may waste material during manufacturing which increases cost and inventory on-hand. Suitable known joining methods may be limited and require a significant capital investment in equipment.
The limitations, disadvantages and drawbacks associated with previously known axle and wheel end assemblies make it desirable to provide an improved axle and wheel end assembly and a method of manufacturing the improved axle and wheel end assembly.